tests/test_keyword_cipher.py

   1 import pytest
   2 import string
   3
   4 from szyfrow.keyword_cipher import *
   5 from szyfrow.support.utilities import *
   6
   7 def test_cipher_alphabet():
   8     assert keyword_cipher_alphabet_of('bayes') == 'bayescdfghijklmnopqrtuvwxz'
   9     assert keyword_cipher_alphabet_of('bayes', KeywordWrapAlphabet.from_a) == 'bayescdfghijklmnopqrtuvwxz'
  10     assert keyword_cipher_alphabet_of('bayes', KeywordWrapAlphabet.from_last) == 'bayestuvwxzcdfghijklmnopqr'
  11     assert keyword_cipher_alphabet_of('bayes', KeywordWrapAlphabet.from_largest) == 'bayeszcdfghijklmnopqrtuvwx'
  12
  13
  14 def test_encipher_message():
  15     enciphered = keyword_encipher('test message', 'bayes')
  16     expected = 'rsqr ksqqbds'
  17     assert enciphered == expected
  18
  19     enciphered = keyword_encipher('test message', 'bayes', KeywordWrapAlphabet.from_a)
  20     expected = 'rsqr ksqqbds'
  21     assert enciphered == expected
  22
  23     enciphered = keyword_encipher('test message', 'bayes', KeywordWrapAlphabet.from_last)
  24     expected = 'lskl dskkbus'
  25     assert enciphered == expected
  26
  27     enciphered = keyword_encipher('test message', 'bayes', KeywordWrapAlphabet.from_largest)
  28     expected = 'qspq jsppbcs'
  29     assert enciphered == expected
  30
  31
  32 def test_decipher_message():
  33     plaintext = 'test message'
  34     for key in ['bayes', 'samplekey']:
  35         for wrap in KeywordWrapAlphabet:
  36             enciphered = keyword_encipher(plaintext, key, wrap)
  37             deciphered = keyword_decipher(enciphered, key, wrap)
  38             assert deciphered == plaintext
  39
  40
  41 def test_keyword_break():
  42     plaintext = 'this is a test message for the keyword breaking routine'
  43     expected_key = 'elephant'
  44     expected_wrap = KeywordWrapAlphabet.from_last
  45     ciphertext = keyword_encipher(plaintext, expected_key, expected_wrap)
  46     (key, wrap), score = keyword_break(ciphertext,
  47         wordlist=['cat', 'elephant', 'kangaroo'])
  48     assert key == expected_key
  49     assert wrap == expected_wrap
  50     assert score == pytest.approx(Pletters(sanitise(plaintext)))
  51
  52 def test_keyword_break_mp():
  53     plaintext = 'this is a test message for the keyword breaking routine'
  54     expected_key = 'elephant'
  55     expected_wrap = KeywordWrapAlphabet.from_last
  56     ciphertext = keyword_encipher(plaintext, expected_key, expected_wrap)
  57     (key, wrap), score = keyword_break_mp(ciphertext,
  58         wordlist=['cat', 'elephant', 'kangaroo'])
  59     assert key == expected_key
  60     assert wrap == expected_wrap
  61     assert score == pytest.approx(Pletters(sanitise(plaintext)))
  62
  63
  64 # def test_simulated_annealing_break():
  65 #     # random.seed(0)
  66 #     plaintext = '''You will rejoice to hear that no disaster has accompanied the
  67 #     commencement of an enterprise which you have regarded with such evil
  68 #     forebodings.  I arrived here yesterday, and my first task is to assure
  69 #     my dear sister of my welfare and increasing confidence in the success
  70 #     of my undertaking.
  71
  72 #     I am already far north of London, and as I walk in the streets of
  73 #     Petersburgh, I feel a cold northern breeze play upon my cheeks, which
  74 #     braces my nerves and fills me with delight.  Do you understand this
  75 #     feeling?  This breeze, which has travelled from the regions towards
  76 #     which I am advancing, gives me a foretaste of those icy climes.
  77 #     Inspirited by this wind of promise, my daydreams become more fervent
  78 #     and vivid.
  79
  80 #      I try in vain to be persuaded that the pole is the seat of
  81 #     frost and desolation; it ever presents itself to my imagination as the
  82 #     region of beauty and delight.  There, Margaret, the sun is for ever
  83 #     visible, its broad disk just skirting the horizon and diffusing a
  84 #     perpetual splendour.  There—for with your leave, my sister, I will put
  85 #     some trust in preceding navigators—there snow and frost are banished;
  86 #     and, sailing over a calm sea, we may be wafted to a land surpassing in
  87 #     wonders and in beauty every region hitherto discovered on the habitable
  88 #     globe.
  89
  90 #     Its productions and features may be without example, as the
  91 #     phenomena of the heavenly bodies undoubtedly are in those undiscovered
  92 #     solitudes.  What may not be expected in a country of eternal light?  I
  93 #     may there discover the wondrous power which attracts the needle and may
  94 #     regulate a thousand celestial observations that require only this
  95 #     voyage to render their seeming eccentricities consistent for ever.  I
  96 #     shall satiate my ardent curiosity with the sight of a part of the world
  97 #     never before visited, and may tread a land never before imprinted by
  98 #     the foot of man. These are my enticements, and they are sufficient to
  99 #     conquer all fear of danger or death and to induce me to commence this
 100 #     laborious voyage with the joy a child feels when he embarks in a little
 101 #     boat, with his holiday mates, on an expedition of discovery up his
 102 #     native river.
 103
 104 #     But supposing all these conjectures to be false, you cannot contest the
 105 #     inestimable benefit which I shall confer on all mankind, to the last
 106 #     generation, by discovering a passage near the pole to those countries, to
 107 #     reach which at present so many months are requisite; or by ascertaining the
 108 #     secret of the magnet, which, if at all possible, can only be effected by an
 109 #     undertaking such as mine.'''
 110
 111 #     expected_key = keyword_cipher_alphabet_of('abced')
 112 #     ciphertext = keyword_encipher(sanitise(plaintext), expected_key)
 113 #     expected_score = Ptrigrams(sanitise(plaintext))
 114 #     actual_key, actual_score = monoalphabetic_sa_break(ciphertext,
 115 #         plain_alphabet=string.ascii_lowercase,
 116 #         cipher_alphabet=string.ascii_lowercase,
 117 #         workers=10, max_iterations=1000,
 118 #         fitness=Ptrigrams
 119 #         )
 120 #     assert expected_key == actual_key
 121 #     assert expected_score == pytest.approx(actual_score)